Random Access Preamble Grouping for Wireless Resource Allocation

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Solution Overview

Problem

In wireless communication systems like LTE, wireless devices face challenges in initiating contact with the network without a dedicated uplink resource, as existing random access preamble grouping methods do not effectively account for varying transmission sizes and coverage conditions, leading to inefficient resource allocation and potential random access failures.

Innovation Solution

The method involves grouping random access preambles according to different criteria, such as transmission size and coverage enhancement levels, allowing wireless devices to select appropriate preambles for optimal resource allocation and communication, even in challenging conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If random access preambles are grouped into a single group, then device complexity is reduced, but random access reliability deteriorates due to inability to account for varying transmission sizes and coverage conditions

Engineering Contradiction:
Improvepreamble grouping structureVSAvoidrandom access success rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the random access preambles into multiple groups (first group and second group) based on transmission size criteria. The base station configures different numbers of preambles in each group, allowing UEs to select appropriate groups based on their transmission requirements. This segmentation resolves the contradiction by providing structured differentiation that improves reliability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different preamble grouping characteristics to different transmission scenarios. Specifically, the first group is optimized for small transmission sizes while the second group handles larger transmissions, with each group having independently configurable preamble counts. This localized optimization improves random access reliability for each scenario without requiring complex device-side decisions.

Inventive Principle:
Principle #3Local quality

2Reliability

If multiple preamble groups are configured with different criteria, then random access reliability improves, but device complexity increases due to multiple selection criteria

Engineering Contradiction:
Improverandom access success rateVSAvoidpreamble selection process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of preamble group configuration by allowing the base station to independently set the number of preambles in the first group (via firstIndicationInformation) and the second group (via secondIndicationInformation). This parameter-based configuration simplifies device complexity because UEs only need to compare their transmission size against configured thresholds and select from pre-defined groups, rather than performing complex multi-criteria evaluations.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If preambles are allocated without considering transmission size, then resource allocation simplicity is maintained, but resource allocation efficiency deteriorates

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidresource allocation mechanism
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments preamble resources into two distinct groups with different allocation characteristics. The first group is dedicated for small transmission sizes with a configured number of preambles, while the second group handles larger transmissions. This segmentation enables efficient resource allocation by matching preamble group selection to transmission size, improving productivity without requiring complex real-time resource negotiation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by optimizing preamble resource allocation for specific transmission size ranges. Each preamble group is locally optimized for its intended use case, with the base station configuring appropriate preamble counts based on network conditions and traffic patterns. This localized resource optimization improves overall allocation efficiency while keeping the mechanism simple through base-station-side configuration.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3580990B1Random access preamble selection from multiple types of preamble groups
Publication Date: 2022.08.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3580990B1 patent drawingFigure 1
  • EP3580990B1 patent drawingFigure 2
  • EP3580990B1 patent drawingFigure 3

AI summary

Random access preambles (130) are grouped in accordance with one of a plurality of grouping schemes (125). Different grouping schemes (125) are associated with different types of group selection criteria. A wireless device (110) (e.g., a user equipment) determines which one of the plurality of grouping schemes (125) the random access preambles (130) are grouped in accordance with, and selects, from among groups (135) of the random access preambles (130) as defined in accordance with the determined grouping scheme (125), a group (135) based on the type of group selection criteria associated with the determined grouping scheme (125). The wireless device (110) attempts random access to a base station (105) using a random access preamble (120) selected from the selected group (135).